1. Technical Field
The present invention relates to a clamp method of a disk shaped recording medium to a spindle motor in a disk drive device such as a hard disk drive and, more specifically, to a clamp method in which warpage does not occur in a disk shaped recording medium.
2. Description of the Related Art
In a hard disk drive (hereinafter referred to as an HDD), which is most general data storage means for a computer, has a structure in which a single disk shaped recording medium or a plurality of disk shaped recording media are arranged coaxially and in which the disk shaped recording medium or media are driven by a spindle motor. Read and write operations of data are carried out by a magnetic head provided so as to face the disk shaped recording medium, and the magnetic head is driven by an actuator, which is a voice coil motor (hereinafter referred to as a VCM) in general. The disk shaped recording medium or media, the magnetic head, and the actuator are contained in a case which is called an enclosure case.
The base has a circuit board fastened on a back surface thereof. The circuit board is mounted with elements for controlling the spindle motor, the VCM, and the like. The circuit board is provided with an interface cable connector for establishing a connection with a computer apparatus which serves as a host. At a position on a far side of the interface cable connector, a preamplifier connector is provided. The reason why the preamplifier connector is located on the far side of the interface cable connector as described above is that a wiring distance between the preamplifier connector and the preamplifier can be shortened. On the other hand, the reason why the interface cable connector is located on the same side of the spindle motor is that the above described arrangement is thought to be best based on electrical constraints such as an intensity of a signal, digital or analog, and a noise, along a flow of the signal viewed from the interface cable connector, and based on geometrical constraints such as a position and a size of the VCM included in the enclosure case.
Heretofore, by improving a flatness of a contact surface between a disk shaped recording medium and a clamp, the above described problem has been coped with. However, in view of a production cost of a clamp, there is a limit to significantly improving the flatness.